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[4/7] KVM: x86: hyper-v: always advertise HV_STIMER_DIRECT_MODE_AVAILABLE

Message ID 20200807083946.377654-5-vkuznets@redhat.com (mailing list archive)
State New, archived
Headers show
Series KVM: x86: hyper-v: make KVM_GET_SUPPORTED_HV_CPUID more useful | expand

Commit Message

Vitaly Kuznetsov Aug. 7, 2020, 8:39 a.m. UTC
HV_STIMER_DIRECT_MODE_AVAILABLE is the last conditionally set feature bit
in KVM_GET_SUPPORTED_HV_CPUID but it doesn't have to be conditional: first,
this bit is only an indication to userspace VMM that direct mode stimers
are supported, it still requires manual enablement (enabling SynIC) to
work so no VMM should just blindly copy it to guest CPUIDs. Second,
lapic_in_kernel() is a must for SynIC. Expose the bit unconditionally.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/hyperv.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 5a6831799544..a8ebaa66a8e1 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2027,13 +2027,7 @@  int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid,
 			ent->ebx |= HV_DEBUGGING;
 			ent->edx |= HV_X64_GUEST_DEBUGGING_AVAILABLE;
 			ent->edx |= HV_FEATURE_DEBUG_MSRS_AVAILABLE;
-
-			/*
-			 * Direct Synthetic timers only make sense with in-kernel
-			 * LAPIC
-			 */
-			if (lapic_in_kernel(vcpu))
-				ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
+			ent->edx |= HV_STIMER_DIRECT_MODE_AVAILABLE;
 
 			break;